Screw driver



N. scHELoT ET A1. 2,084,220

SCREW DRIVER June 15, 1937.

Filed Oct. 22, 1936 ATTORNEYS Patented .une 15, 1937 UNITED STATES SCREW DRIVER Norbert Schelot and Elmer E. Vahle, St. Louis, M0.

Application October 2.2, 1936, Serial No. 107,093

3 Claims.

'Ihis invention relates to screw drivers especially adapted for driving tempered screws into metallic bodies and has for the primary object the provision of a device of this character wherein the bit thereof is of a tempered material and adjustable and removable from the device so that as the bit wears it may be advanced into working position and when worn to an extent to render it unfit for further use will be automatically released to permit the placing in the device of a new bit of a similar construction.

With these and other objects in view, this invention consists in certain novel features of construction, combination and arrangement of parts to be hereinafter more fully described and claimed.

For a complete understanding of our invention, reference is to be had to the following description and accompanying drawing, in which v Figure 1 is a fragmentary side elevation illustrating a screw driver constructed in accordance with our invention. l

Figure 2 is a view similar to Figure l, only partly in section, showing the head of the holding device for the bit.

Figure 3 is a vertical sectional View illustrating the device.

Figure 4 is a sectional View taken on the line 4-4 of Figure 1.

Figure 5 is a plan view illustrating a bit orl blade.

Referring in detail to the drawing, the numeral I indicates an externally screw threaded body of cylindrical formation, one end (not shown) is constructed to t a chuck of a power driven tool or if desired may be secured in a handle. Mounted on the other end of the body and secured thereto by a pin 2 is a head 3 of substantially spherical shape provided with oppositely disposed beveled faces 4 and a flat face 5. The body I has a slot 6 extending therethrough and opening outwardly through the last-named end of the body or the end on which the head 3 is mounted. The flat face 5 of the head has a slot aligning with the slot 6. Mounted in the slot 6 and protruding therefrom by way of the slot in the face 5 of the head is a bit or blade 1 having a work-engaging end 8 and oppositely arranged notches 9 located adjacent the other end thereof. The work engaging end of the bit or 50 with one end of the nut and the key or follower engages the other end of the nut. A lock nut I5 is threaded on the body to hold the strap against the nut I4.

In operation, as the working end 8 of the bit or blade wears from use the latter may be advanced outwardly of the head by adjusting the nut I4 on the body and when the bit or blade is Worn to an extent that it is unfit for further use the angularly disposed ends of the strap I2 will ride on the curved faces of the head 3 and thereby become disengaged from the notches 9 and permit the bit or blade to pass freely from the slot 6.

Having described the invention, we claim:

l. A screw driver comprising a body having one end constructed to t a tool chuck and provided with a slot opening outwardly through the opposite end thereof, a bit received in said slot and protruding therefrom at said last-named end of the body, a nut threaded on the body, said bit having notches, a substantially U-shaped strap engageable with the nut and extending through the slot and having its ends bent angularly to engage in the notches, a follower engaging the nut and the bit and having forked ends to receive thev strap.

2. A screw driver comprising a body having one end constructed to fit a tool chuck and provided with a slot opening outwardly through the opposite end thereof, a bit received in said slot and protruding therefrom at said last-named end of the body, a nut threaded on the body, said bit having notches, a substantially U-shaped strap engageable with the nut and extending through the slot and having its ends bent angularly to engage in the notches, a follower engaging the nut and the bit and having forked ends to receive the strap, and a second nut threaded on the body to force the strap against the firstnamed nut.

3. A screw driver comprising a body having one end constructed to fit a tool chuck and provided with a slot opening outwardly through the opposite end thereof, a bit received in said slot and protruding therefrom at said last-named end of the body, a nut threaded on the body, said bit having notches, a substantially U-shaped strap engageable with the nut and extending through the slot and having its ends bent angularly to engage in the notches, a follower engaging the nut and the bit and having forked ends to receive the strap, a second nut threaded on the body to force the strap against the first-named nut, and a substantially spherical shaped head secured to the body to be engaged by the angularly related ends of the strap when said bit is substantially advanced outwardly of the body for disengaging said ends of the strap from the bit.

NORBERT SCHELOT. ELMER E. VAI-ILE. 

